This is more logical and allows us to solve the problem of
non-blocking TCP sockets getting stuck in SocketRole::None.
The only complication is that a single LocalSocket may be shared
between two file descriptions (on the connect and accept sides),
and should have two different roles depending from which side
you look at it. To deal with it, Socket::role() is made a
virtual method that accepts a file description, and LocalSocket
internally tracks which FileDescription is the which one and
returns a correct role.
Now that there can't be multiple clones of the same fd,
we only need to track whether or not an fd exists on each
side. Also there's no point in tracking connecting fds.
After a fork, the parent and the child are supposed to share
the same file description. For example, modifying the current
offset of a file description is visible in both of them.
Committing some things my hands did while browsing through this code.
- Mark all leaf classes "final".
- FileDescriptionBlocker now stores a NonnullRefPtr<FileDescription>.
- FileDescriptionBlocker::blocked_description() now returns a reference.
- ConditionBlocker takes a Function&&.
This is obviously more readable. If we ever run into a situation where
ref count churn is actually causing trouble in the future, we can deal with
it then. For now, let's keep it simple. :^)
After reading a bunch of POSIX specs, I've learned that a file descriptor
is the number that refers to a file description, not the description itself.
So this patch renames FileDescriptor to FileDescription, and Process now has
FileDescription* file_description(int fd).
2019-06-07 09:36:51 +02:00
Renamed from Kernel/FileSystem/FileDescriptor.cpp (Browse further)
